Pigment and paint composition.



titanium, silica, and the like.

gree.

UNITED STATES PATENT OEEIcE.

CORNELIUS D. VREELAND, OF CHICAGO HEIGHTS, ILLINOIS.

PIGMENT AND PAINT COMPOSITION.

SPECIFICATION forming part of Letters Patent No. 691,422, dated January21, 1902.

Application filed August 1d, 1900. Renewed December 12,1901. Serial No.85,666. (No specimens.)

To (all whom, it may concern:

Be it known that I, CORNELIUS D. VREE- LAND, a citizen of the UnitedStates, residing at Chicago Heights, in the county of Cook, in

5 the State of Illinois, have invented a new and useful Improvement inCompositions of Matter; and I do hereby declare that the following is afull, clear, and exact description of the same.

This invention relates to the utilization of the waste product whichresults from the manufacture of sulfate of alumina from bauxite. Thislatter material is composed of hydroxid of alumina, with more or lessoxid of iron, In the acid process aforesaid the bauxite ore is firsttreated with dilute sulfuric acid. The solution of sulfate of aluminathus produced is then allowed to settle and then filtered. From this 20results a precipitate prior to filtration and a residue which is caughtand retained by the filter. This residue maybe added to the precipitate,as for the purposes of inyinvention it difiers from the latter in noessential de- I include each material in the general term sludge, whichwhen freed from acid either by washing with water or by neutralizationby means of an alkali is the material from which the paint comprised inmy invention is made.

cially known by various names-for example,

as paper-makers alum, filter alum, concentrated alum, alum cake, the.)and eliminate therefrom its acid constituents either by suflicientlyprofuse washing with water or by treating the material with milk oflime. This latter results in the production of some sulfate of lime, thepresence of which, however, in the material does no harm. The

. neutralization of the acid constituents of the sludge also results inthe decomposition of whatever sulfate of alumina may have remained inthe sludge and causes it to be deposited in gelatinous form. This whendried with the rest of the material forms, to such extent as may be, anelement thereof. In whatever manner the acid constituents of the sludgeare eliminated from the latter the sludge after eliminationisbrought toagreater or less condition of dryness, meaning thereby a condition inwhich it may be readily incorporated or ground with other materialas,for example, for the production of paint. It will be observed that bythe treatment described the character of the original sludge is entirelychanged from that of a semiliquid and waste product of no known utilityto that of a dry, neutral, pulverulent, or powdered material adapted forimmediate use in various arts and industries. The drying may beaccomplished by any suitable means. This neutral and dried sludge ismade pulverulent or powdered in any suitable Way. For the manufacture ofpaint the neutral and dried sludge is ground in oil in an ordinarypaint-mill or in any other suitable manner, and being thus intimatelyincorporated with the oil constitutes an excellent paint, whichmayreceive various tints or colors by the addition of suitable pigments orcoloring-matter. I thus by my said invention produce a paint ofexcellent character from a material that has hitherto been waste andcommonly regarded as worthless.

What I claim as my invention is- 1. As a new article of manufacture, theherein described dry, neutral, pulverulent or powdered product obtainedfrom the sludge resulting from the production of sulfate of alumina bythe acid process, as set forth.

2. As a new article of manufacturea paint composed of dried neutralsludge derived from the production of sulfate of alumina by the acidprocess, ground in oil, substantially as herein set forth.

CORNELIUS D. VREELAND.

lrVitnesses:

DANIEL S. DECKER, J AMES A. WHITNEY.

